Balanced weft tension for loom shuttles



March 20, 1951 TURNER 2,545,934

BALANCED WEFT TENSION FOR LOOM SHUTTLES Filed Nov. 6, 1948 FEQDE PIC-3.3

INVENTOR RICHARD G. TURNER ATTORNEY .provided which extend into holesformed in the threader Patented Mar. 20, 1951 BALANCED WEFT TENSION FORLOOM SHUTTLES Richard G. Turner, Worcester,

Crompton & Knowles Loom Works,

Mass, assignor to Worcester,

Mass, a corporation of Massachusetts Application November 6, 1948,Serial No. 58,736

This invention relates to weft tensions for loom shuttles and it is thegeneral object of the inhood of cutting of the weft.

A form of weft tension which has gone into general use employs a pair ofpads which are spring pressed toward the weft which passes between thepads. The lower ends of these pads are loosely mounted for limited freemovement about a supporting pin and their upper ends are with laterallyextending guide fingers block of the shuttle. The pads have verticallyextending flat friction surfaces which generally terminate in straightvertical edges. When the shuttle is checked near the end of its flightthe laterally extending fingers due to their momentum rock the pads insuch manner that the weft is pinched between adjacent vertical edges ofthe flat friction faces. When fine weft is used this pinching may causesufficient weakening of the thread to cause it to break on the next pickof the shuttle.

It is an important object of the present invention to provide the padswith counterbalances or the like the effect of which is to oppose thetendency of the laterally extending fingers to turn the pads when theshuttle is checked. These counterweights may take the form of extensionsat the bottoms of the pads and each 'pad will be formed with a fiatfriction surface with its guide finger and counterweight located onopposite sides of the surface.

It is a further object of the invention to provide an improved tensionpad which will be dynamically balanced about a vertical line extendingalong the friction surface thereof.

It is a further object of the invention to place one ofthecounterweights in such position that it will act as a guard toprevent the weft from falling between the supporting pin and one or theother of the pads where it might be cut.

With these and other objects in view which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein a convenient embodiment of theinvention is set forth,

Fig. 1 is a plan view of one end of a shuttle made according to thepresent invention,

Fig. 2 is an enlarged vertical section on line 2-2 of Fig.1.

5 Claims. (Cl. 139-217) Fig. 3 is a plan view of the pads looking in thedirection of arrow 3', Fig. 2, and

Fig. 4 is a perspective view of the two pads used in the shuttletension.

As shown in Figs. 1 and 2, the shuttle S has a'bobbin compartment Ill inwhich is located a bobbin B from which the weft W unwinds when theshuttle is in flight. The weft passes through a threader block I isecured to the shuttle in any approved manner and issues from a deliveryeye !2 which is generally located in relatively low position on thefront wall of the shuttle. To accommodate the weft the shuttle block isprovided with a thread passage l3 which extends in a directionlongitudinally of the shuttle and is open at its upper end to receivethe thread.

Extending transversely of the threader block I I is a guide orsupporting pin 15 on which front and back tension pads l6 and I1respectively are mounted for limited free motion. In order to providethis motion the lower end of each pad is provided with a hole iii thediameter of which is slightly larger than the diameter of the pin I5.The upper end of pad It is provided with a laterally extending fingerwhich extends into a hole 21 in the front wall 22 of the threader blockII, and in similar manner the upper end of pad I! is provided with alaterally extending guide finger 23 extending into a hole 24 in the backwall 25 of the threader block. The fingers 20 and 23 have a loose fitwith their corresponding holes and this fact together with the manner ofmounting the pads on the pin l5 permits the pads to have limited freemovement both vertically and horizontally in a direction lengthwise ofthe shuttle.

Each pad is provided with means for urging it toward the other pad, thismeans generally comprising a light spring. As shown more particularly inFig. 2 front wall 22 has threaded thereinto a screw 26 which backs up aweak compression spring 2'! which bears rearwardly against the front padIt, and similarly the rear wall 25 is provided with a screw 28 whichbacks up a spring 29 for the rear pad l1. These two springs are ofapproximately the same strength and urge the pads toward each other sothat the vertical friction substantially fiat surface 29 of the frontpad [6 will be held against a similar surface 30 on the rear pad H. Theweft thread =ordinarily passes between the two pads and the springsacting through the pads exert a frictional force on the weft whichtensions it.

The matter thus far described is of common construction but is so madethat in operation the offset or laterally extending guide fingers 2!]and 23 cause slight angular motions of the pads around a vertical axiswhen the shuttle is checked near the end of its flight, thereby pinchingthe weft and weakening it so that it is likely to break in the next pickof the shuttle.

In carrying the present invention into effect each pad is provided witha lateral extension which counterbalances the guide finger thereof. Asshown in Fig. 4 the front pad [6 has the lower end thereof formed with alateral extension 35 extending to the left or in a direction opposite tothat in which the guide finger 20 extends. The lower rear wall 25 of thethreader block can have a portion thereof removed if desired to define arecess 36 to accommodate the counterweight 35. The lower end of the rearpad I1 is provided with a forwardly extending counterweight or wing 31which occupies a recess 38 in the lower part of the front wall 22 of thethreader block I I.

These laterally extending wings or counterweights 35 and 3"! are made ofsuch size that their Weight will counteract the tendency of the guidefingers 20 and 23 to rock or turn the pads as already described when theshuttle is checked near the end of its flight. Thus, as the shuttle ischecked the guide finger 26 of the front pad tends by its momentum tomove the pad 16 angularly around one or the other of its vertical edges4i! as an axis, but the counterweight 35 exerts the same tendency exceptthat it tries to turn a pad angularly in the opposite direction with thenet result that the two tendencies to turn are counteracted and the padretains its normal position even though the shuttle suffers a sharpreduction in its speed when being checked. Similarly, the counterweightor wing 31 offsets the tendency of the guide finger 23 to turn the rearpad around one or the other of its vertical edges 4! as an axis.Throughout the flight of the shuttle therefore normal tension ispreserved on the weft without regard to changes in the rate of travel ofthe shuttle. By referring to Fig. 2 it will be seen that the top edge 42of wing 31 extends across the front pad at a level above supporting pin15 and thus keeps the weft W from falling onto the pin where it might becut by the pads as they move laterally of the shuttle.

From the foregoing it will be seen that the invention sets forth simplemeans, such as counterweights, by which the pads of the shuttle tensionare prevented from being moved angularly due to the momentum of theirguide fingers when the shuttle is checked. It will also be seen that thecounterweights or wings do not interfere with normal passage of the weftbetween the pads and through the thread passage l3. Furthermore, thecounterweight 3! as shown more particularly in Fig. 2 extends from therear pad ll forwardly across the space between the vertical faces of thepads ordinarily occupied by the weft and prevents the latter fromfalling to the level where it might be pinched between the pads and theguide pin l5. Also, the invention sets forth a tension pad which isdynamically balanced about a vertical axis extending preferably alongthe weft engaging friction surface thereof.

Having thus described the invention it will be seen that changes andmodifications of the foregoing specific disclosure may be. made withoutdeparting from the spirit and scope of the invention.

What is claimed as new is:

1. In weft tension mechanism for a loom shuttle having a threader block,a pair of vertically extending tension pads mounted on the block, alaterally extending finger on each pad effective due to momentum thereoftending when the shuttle is checked near the end of its flight to tendto cause angular movement of the pad, and a counterweight on each pad onthe side thereof opposite the corresponding finger and movablerelatively to the shuttle and counteracting the tendency of thecorresponding finger to cause said angular movement.

2. In weft tension mechanism for a loom shuttle having a threader block,a pair of vertically extending tension pads mounted on the block, alaterally extending finger on at least one of said pads tending due tothe momentum thereof to cause angular movement of said one pad when theshuttle is checked near the end of its flight, and a counterweight onsaid one pad movable relatively to the shuttle on the side of the padopposite said finger effective due to the momentum thereof when theshuttle is checked to prevent said finger from causing said angularmovement.

3. In weft tension mechanism for a loom shuttle having a threader block,front and back vertically extending tension pads mounted on the threaderblock, a finger extending forwardly from the front pad into the blockand a second finger extending rearwardly from the back pad, said fingersdue to their momentum tending to cause angular movements of theircorresponding pads when the shuttle is checked in its flight, acounterweight on the front pad extending rearwardly therefrom, and asecond counterweight on the back pad extending forwardly therefrom, saidcounterweights preventing the fingers from causing said angularmovements of said pads when the shuttle is checked.

4. In weft tension mechanism for a loom shuttle having a threader block,a pair of vertically extending tension pads mounted on the block, aguide pin on the block for the lower ends of said pads, a laterallyextending finger on at least one of said pads tending when the shuttleis checked to cause angular movement of said one pad, and acounterweight on said one pad preventing the finger from causing saidangular movement and extending above said guide pin and under the weftto keep the latter above and out of engagement with the guide pin.

5. In weft tension mechanism for a loom shuttle having a threader block,a pair of vertically extending tension pads mounted on the block, alaterally extending finger on each pad tending due to the momentumthereof when the shuttle is checked near the end of its flight to causeangular movement of the pad, and a counterweight on each pad movablerelatively to the shuttle and effective due to the momentum thereof whenthe shuttle is checked to counteract the tendency of the correspondingfinger to cause said angular movement, the counterweight of one of saidpads extending across the other pad in position to support a Weft threadbetween said pads.

RICHARD G. TURNER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

